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| 1 | +// SPDX-License-Identifier: GPL-2.0-only |
| 2 | +// Miscellaneous Arm SMMU implementation and integration quirks |
| 3 | +// Copyright (C) 2019 Arm Limited |
| 4 | + |
| 5 | +#define pr_fmt(fmt) "arm-smmu: " fmt |
| 6 | + |
| 7 | +#include <linux/bitfield.h> |
| 8 | +#include <linux/of.h> |
| 9 | + |
| 10 | +#include "arm-smmu.h" |
| 11 | + |
| 12 | + |
| 13 | +static int arm_smmu_gr0_ns(int offset) |
| 14 | +{ |
| 15 | + switch(offset) { |
| 16 | + case ARM_SMMU_GR0_sCR0: |
| 17 | + case ARM_SMMU_GR0_sACR: |
| 18 | + case ARM_SMMU_GR0_sGFSR: |
| 19 | + case ARM_SMMU_GR0_sGFSYNR0: |
| 20 | + case ARM_SMMU_GR0_sGFSYNR1: |
| 21 | + case ARM_SMMU_GR0_sGFSYNR2: |
| 22 | + return offset + 0x400; |
| 23 | + default: |
| 24 | + return offset; |
| 25 | + } |
| 26 | +} |
| 27 | + |
| 28 | +static u32 arm_smmu_read_ns(struct arm_smmu_device *smmu, int page, |
| 29 | + int offset) |
| 30 | +{ |
| 31 | + if (page == ARM_SMMU_GR0) |
| 32 | + offset = arm_smmu_gr0_ns(offset); |
| 33 | + return readl_relaxed(arm_smmu_page(smmu, page) + offset); |
| 34 | +} |
| 35 | + |
| 36 | +static void arm_smmu_write_ns(struct arm_smmu_device *smmu, int page, |
| 37 | + int offset, u32 val) |
| 38 | +{ |
| 39 | + if (page == ARM_SMMU_GR0) |
| 40 | + offset = arm_smmu_gr0_ns(offset); |
| 41 | + writel_relaxed(val, arm_smmu_page(smmu, page) + offset); |
| 42 | +} |
| 43 | + |
| 44 | +/* Since we don't care for sGFAR, we can do without 64-bit accessors */ |
| 45 | +static const struct arm_smmu_impl calxeda_impl = { |
| 46 | + .read_reg = arm_smmu_read_ns, |
| 47 | + .write_reg = arm_smmu_write_ns, |
| 48 | +}; |
| 49 | + |
| 50 | + |
| 51 | +struct cavium_smmu { |
| 52 | + struct arm_smmu_device smmu; |
| 53 | + u32 id_base; |
| 54 | +}; |
| 55 | + |
| 56 | +static int cavium_cfg_probe(struct arm_smmu_device *smmu) |
| 57 | +{ |
| 58 | + static atomic_t context_count = ATOMIC_INIT(0); |
| 59 | + struct cavium_smmu *cs = container_of(smmu, struct cavium_smmu, smmu); |
| 60 | + /* |
| 61 | + * Cavium CN88xx erratum #27704. |
| 62 | + * Ensure ASID and VMID allocation is unique across all SMMUs in |
| 63 | + * the system. |
| 64 | + */ |
| 65 | + cs->id_base = atomic_fetch_add(smmu->num_context_banks, &context_count); |
| 66 | + dev_notice(smmu->dev, "\tenabling workaround for Cavium erratum 27704\n"); |
| 67 | + |
| 68 | + return 0; |
| 69 | +} |
| 70 | + |
| 71 | +static int cavium_init_context(struct arm_smmu_domain *smmu_domain) |
| 72 | +{ |
| 73 | + struct cavium_smmu *cs = container_of(smmu_domain->smmu, |
| 74 | + struct cavium_smmu, smmu); |
| 75 | + |
| 76 | + if (smmu_domain->stage == ARM_SMMU_DOMAIN_S2) |
| 77 | + smmu_domain->cfg.vmid += cs->id_base; |
| 78 | + else |
| 79 | + smmu_domain->cfg.asid += cs->id_base; |
| 80 | + |
| 81 | + return 0; |
| 82 | +} |
| 83 | + |
| 84 | +static const struct arm_smmu_impl cavium_impl = { |
| 85 | + .cfg_probe = cavium_cfg_probe, |
| 86 | + .init_context = cavium_init_context, |
| 87 | +}; |
| 88 | + |
| 89 | +static struct arm_smmu_device *cavium_smmu_impl_init(struct arm_smmu_device *smmu) |
| 90 | +{ |
| 91 | + struct cavium_smmu *cs; |
| 92 | + |
| 93 | + cs = devm_kzalloc(smmu->dev, sizeof(*cs), GFP_KERNEL); |
| 94 | + if (!cs) |
| 95 | + return ERR_PTR(-ENOMEM); |
| 96 | + |
| 97 | + cs->smmu = *smmu; |
| 98 | + cs->smmu.impl = &cavium_impl; |
| 99 | + |
| 100 | + devm_kfree(smmu->dev, smmu); |
| 101 | + |
| 102 | + return &cs->smmu; |
| 103 | +} |
| 104 | + |
| 105 | + |
| 106 | +#define ARM_MMU500_ACTLR_CPRE (1 << 1) |
| 107 | + |
| 108 | +#define ARM_MMU500_ACR_CACHE_LOCK (1 << 26) |
| 109 | +#define ARM_MMU500_ACR_S2CRB_TLBEN (1 << 10) |
| 110 | +#define ARM_MMU500_ACR_SMTNMB_TLBEN (1 << 8) |
| 111 | + |
| 112 | +static int arm_mmu500_reset(struct arm_smmu_device *smmu) |
| 113 | +{ |
| 114 | + u32 reg, major; |
| 115 | + int i; |
| 116 | + /* |
| 117 | + * On MMU-500 r2p0 onwards we need to clear ACR.CACHE_LOCK before |
| 118 | + * writes to the context bank ACTLRs will stick. And we just hope that |
| 119 | + * Secure has also cleared SACR.CACHE_LOCK for this to take effect... |
| 120 | + */ |
| 121 | + reg = arm_smmu_gr0_read(smmu, ARM_SMMU_GR0_ID7); |
| 122 | + major = FIELD_GET(ID7_MAJOR, reg); |
| 123 | + reg = arm_smmu_gr0_read(smmu, ARM_SMMU_GR0_sACR); |
| 124 | + if (major >= 2) |
| 125 | + reg &= ~ARM_MMU500_ACR_CACHE_LOCK; |
| 126 | + /* |
| 127 | + * Allow unmatched Stream IDs to allocate bypass |
| 128 | + * TLB entries for reduced latency. |
| 129 | + */ |
| 130 | + reg |= ARM_MMU500_ACR_SMTNMB_TLBEN | ARM_MMU500_ACR_S2CRB_TLBEN; |
| 131 | + arm_smmu_gr0_write(smmu, ARM_SMMU_GR0_sACR, reg); |
| 132 | + |
| 133 | + /* |
| 134 | + * Disable MMU-500's not-particularly-beneficial next-page |
| 135 | + * prefetcher for the sake of errata #841119 and #826419. |
| 136 | + */ |
| 137 | + for (i = 0; i < smmu->num_context_banks; ++i) { |
| 138 | + reg = arm_smmu_cb_read(smmu, i, ARM_SMMU_CB_ACTLR); |
| 139 | + reg &= ~ARM_MMU500_ACTLR_CPRE; |
| 140 | + arm_smmu_cb_write(smmu, i, ARM_SMMU_CB_ACTLR, reg); |
| 141 | + } |
| 142 | + |
| 143 | + return 0; |
| 144 | +} |
| 145 | + |
| 146 | +static const struct arm_smmu_impl arm_mmu500_impl = { |
| 147 | + .reset = arm_mmu500_reset, |
| 148 | +}; |
| 149 | + |
| 150 | + |
| 151 | +struct arm_smmu_device *arm_smmu_impl_init(struct arm_smmu_device *smmu) |
| 152 | +{ |
| 153 | + /* |
| 154 | + * We will inevitably have to combine model-specific implementation |
| 155 | + * quirks with platform-specific integration quirks, but everything |
| 156 | + * we currently support happens to work out as straightforward |
| 157 | + * mutually-exclusive assignments. |
| 158 | + */ |
| 159 | + switch (smmu->model) { |
| 160 | + case ARM_MMU500: |
| 161 | + smmu->impl = &arm_mmu500_impl; |
| 162 | + break; |
| 163 | + case CAVIUM_SMMUV2: |
| 164 | + return cavium_smmu_impl_init(smmu); |
| 165 | + default: |
| 166 | + break; |
| 167 | + } |
| 168 | + |
| 169 | + if (of_property_read_bool(smmu->dev->of_node, |
| 170 | + "calxeda,smmu-secure-config-access")) |
| 171 | + smmu->impl = &calxeda_impl; |
| 172 | + |
| 173 | + return smmu; |
| 174 | +} |
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